Magneto



3 Sheets-Sheet MAGNETO Filed De@ 5' 1926 P. BROWN ET AL NOV- 20, 192s.

BY` /L4/ ATTORNEYS,

Nov. 20,19%.' 1,692,718

P. BROWN ET AL MAGNETO Filed Dec. 5, '192e :s she'ets-sheet 5 ATTORNEYS.

Patented Nov. zo, 1928.

UNITED STATES PATENT oFFlcE.

PHELPS BROWN, OF SPRINGFIELD, AND IRA E. HENDRICKSON, 0F WEST SPRING- -FIEL`D, MASSACHUSETTS; SAID HENDRICKSON ASSIGNOR TO WICO ELECTRIC COM- PANY, 0F WEST SPRINGFIELD, MASSACHUSETTS, .A CORPORATION O F MASSA- CHUSETTS.

MAGNETO.

Application led December 3, 1926. Serial No 152,487.

This invention relates to improvements in magnetos and has to do more particularly with features relating to the interrupter mechanism thereof.

The invention, according to one feature thereof, is directed to the problem of spark control in a particular type of magneto, viz, one in which the armature is moved into and out of Contact with magnetic poles and in which the armature may be moved away from its poles in either of two ways,--first entirely by an inelastic transmission of force fromv the engine and, second, initially by such transmission followed by an elastic transmission from the expansion of previously stressed elastic means. The present invention offers as a solution to this problem mechanism whereby kadequate control of the spark may be had with either -form of armature drive. As 'much range of spark control may be had as is desired whether the armay ture is moved away from its poles entirely by said inelastic transmission or partly by said elastic transmission.

Another feature of the invention relates to means for securing' a'variation in timing of the spark produced by the magneto by varying the position of what is ordinarily termed the fixed breaker point. One of the breaker points is moved by, or under the control of, the armature and normally separates from its mating breaker pointat a certain intermediate point in the Hight of the armature away from its poles. By moving the other breaker point, manually or otherwise, toward or away from the first named breaker point the separation of the points may be made to occur later or earlier in the Hight of the armature.

The feature, just referred to, is desirable inany case because the particular breaker point in question, being light, presents much less resistance to movement and therefore a variation of its position may be effected much more easily and with less cumbersome mechanism than can be effected with the other and armature operated point. Aside from this general advantage 1t perm1ts, in a magneto of the type where both spring and direct inof the upper breaker point being varied to provide for advance or retard of spark when direct drive is being used for the armature and the control of the spark, when spring drive is used, being left to other means which vary the time when the armature leaves its poles.

The invention, in another of its broad aspects, relates to a magneto of the general type referred to in United States Letters Patent No. 1,634,135, granted June 28, 1927, to Phelps Brown. In such magneto, there are two magnetic circuits and two armatures with mechanism for moving first one and then the other armature away from its poles and the E. M. F. produced by the flux change due to the movement of one armature away from its poles is merged with that produced by the flux change due to the movement of the other armature toward its poles. rIhe present invention offers a control for a magneto of this particular type in the nature of a single interrupter which causes the E. M. F. produced by each unit to occur simultaneously.

The invention also has for another feature the provision of means for operating one of a pair of cooperating breaker points first from one armature and then from the other armature of a magneto of the type disclosed in said copending application or in other magnetos of the dual armature type.

There are many other details which contribute to the accomplishment of the broad purposes above set forth and these, together with other objects and advantages, will appear in the following description and will be pointed out in the appended claims.

The invention will be disclosed with reference to the accompanying drawings, in which Fig. 1 is a front elevational view of a. magneto embodying the invention, the casing of the magneto being shown in section to reveal they interior;

Fig. 2 is an end elevational viewlooking from the left hand end of Fig. 1,-showing the magneto as it appears with the casing removed;

Fig. 3 is an exterior Aend elevational view looking from the right hand end of Fig. 1': Fig. 4 is a cross sectional view taken on the line 1 4 of Fig. 1 but drawn to a. larger scale:

larger scale;

,tive of the electrical circuits and connections Fig. 5 is a 'fragmentary cross sectional view taken on the line 5-5 of Fig. 1 but drawn to a y a sectional elevational'view taken on the line 6-6 of Fig. 2but drawn to a larger scale; Fig. 7 is asectional bottom plan view taken on the line 7-7 of Fig. 1 but drawn to a larfer scale;

ig. 8 is a Fig. 6 is diagrammatical view illustraof the magneto; l

/ Fig. 9 is a fragmentary sectional elevational view taken lsimilarly to Fig. 6 but showing a modification in the spring support for the lower breaker point; and

Fi 10 is a schematic view showing the control evice positioned to effect' spring drive of the armatures.

The magneto, illustrated herein, involves two units which are connected to work in cooperative relation so that each contributes to,

and assists in, the work performed by the other. The two unit construction, whilel important and preferred, is not essential in so far as all features of the invent-'ion are concerned. Certain features of the invention, as pointed out in the appended claims are, or may be,

entirely independent of the't-wo unit arrange- 30 ment.

These two units, as shown., arey supported by a common frame, driven from a common drive shaft, utilize a' common source of magnetic ilux, and are controlled both mechani-` cally and electrically :from common means. These units, being alike, a description of one only will be necessary and the corresponding parts of the other unit will be designated by the same reference numerals primed. A

Each unit includes a pair of cores,12 (Fig. 1), which are vertically disposed in spaced parallel relation andthe 'upper ends of which a-re'connected to opposite 'pqles of a source 'of magnetic flux, herein exemplified by permanent bar magnets 13. The cores, of course, are built up from suitable laminations in the usual manner except that their upper ends are so shaped' as to encompass the polar ends of the magnets and aiord oppositely disposed recesses to receive the same. Between the lamp inations of cores 12 and those of cores 12 (the latter being located in-back of but spaced from cores 12) are other laminations 14 (Figs. 2

` and 6), which fill the space therebetween, as

clearly shown in Fig. 2, and which are shaped correspondingly with the upper ends of the core laminations to afford magnet receiving recesses,the whole aiording two long, op positely disposed recesses for receiving opposite polar ends of three stacks of permanent har magnets. The magnets of each stack are held in place by wedges 15 which are driven in between two adjacent magnets of each stack and thereby force the upper and lower magy nets of each stack firmly against the endsfofV '12, and two secondary coils 22,

laminations of cores 12 and 12 and laminations 14 are suitably clamped together, as by a series of bolts 16. These bolts also act to secure opposite ends of non-magnetic cross bars 17 and 17 (Figs.'1 and 6) to the upper ends of cores 12 and 12', and these cross bars serve tohold the cores of each set in proper spaced relation. The lower ends of the cores, a's shown in Figs. 1 and 7, are received in recesses formed in a horizontally disposed framemember ,18 and are clamped in such recesses by screws 19.' The cores extend downwardly a short distance belowframe 18 and their bottom faces, which constitute magnetic poles, are adapted to be intermittently connected and disconnected by a reciprocating armature 20.

Each unit also includes two primary coils 21 (Figs. 1 and 7) encompassing each core one encompassing each c'oil 21. The. coils 21 and 22 and the correspondingcoils 21 and 22 are housed in recesses formed in a common block 23 o't' bakelite or other similar or suitable material, which block fits snugly between frame 18 and the cross bars 17. The primary coils 21 may be connected .in any suitable way to un'ctionas one choke winding. A s shown in Fig. 8, they are connected in electrical secontact with metallic parts of the machine, is

likewise grounded. 'The other terminal of each choke winding is connected by a wire 27 to the breaker p oint 26, which asl will'- appear is insulated from the metallic'parts' ries by a wire 24.-. The two choke windings,

of the machine. A condenser 28 is rovided,

one terminal of which is grounde and the other connected by: a wire 29 to breaker point 26.

The secondary coils 22, constituting the generating winding, are suitably connected,

" as in electrical series, by a wire 30 andthe two generating windings, comprising the connected coils 22'and the connected coils 22" are connected in any suitable way so that the currents simultaneously produced in cach are merged. As shown, the two windings are connected in series by a wire 31 so that the lll) electromotive force produced in each is added.

The terminals of the generating winding are connected to a suitable distributer D, which 'functions to successively connect the generating winding at properly timed intervals to a series of spark plugs s. I The distributer, illustrated herein, involves -an insulating panel 32 (Fig. 6) which issecured to oneend of frame member 18 and car-r' ries four contacts 33 arranged 1n upper and" lower pairs. An insulating arm 34 pivoted tofram'e 18 at 35 (see also yFig. 3) oscillates back and forth between these pairs lof contacts and carries conducting pieces 36 and 37 to simultaneously engage one l'contact of each-pair.' 'The two terminals of the generating winding are thus successively connected to pairs of spark plugs but the plugs of each pair are arranged in series and one of them produces' a spark on the firing, stroke and the other near the end of the exhaust stroke. An insulatingv block 38.l held in place by the casing C of the magneto, encompasses the contacts 33 and has sockets to receive the spark plug wires 39 and carries springs 40 to connect such wires to'the contacts 33. The

` construction and operation of t-he distributer gage the lower flange is not essential to the present invention and is herein shown and briefiy referred to merely to complete the description and disclosure of the ignition apparatus.

The interrupter, referred to, is mounted near one end ofthe machine, being the end opposite from that at which the distributer is located. The interrupter is supported from the center-of a cross bar 41 (Fig. 5) which in turn is supported near opposite ends through the intermediary of spacing sleeves 42 from posts 43, formed integrally with and upstanding from the frame member 1S. Screws 44, passino' through bar 41 and sleeves 42 are threaded into posts 43 and serve to clamp bar 41 thereto. The central portion of bar 41 has an opening therein into which a busha ing 45 is tightly driven. rlhis bushing slidmally held stationary in the illustra-ted position but can be moved downwardly when reuired, thereby stressing the spring 49 so t 'at the latter will subsequently, when permitted, return the casing back to the normal position. Means, later to be described, en-

48 for the purpose of lowering casing 46. The upper end of casing-46Jvhich is closed,

serves to support the breaker point 26,-the .latter being adjustably fixed to and insulated from said end. The. other breaker point 25 is fixed to the upper end of a plunger 50 which slidably fits thebore of casing 46.' The plunger 50 is adjustably fixed to a threaded stem 51 the lower end of which has a flanged plug 5-1 (Fig. 6) to slipv into ahole in the upper endof a hollow rect-angular support .52. v,'Jfhelattgeiz is urged upwardlyby a spring upper ange 47 of the in-. terrupter casing, wherebythe latter is nor- (see Fig. 6).

53, which serves to hold plug 51' in its hole and which normally tends to hold breaker point 25 in 'en agement with its matingpoint 26. The brea er point 25 is in metallic connection with the frame 18 and therefore grounded.

Referring now to the armature operatingmechanism, the 'armature 2O is fixed by bolts 55 (Figs. land 7) to an arm 56and a plate 57,-the latter serving to move breaker point 25 as will later appear. The arm 56, at one end, is mounted on a stud 58, fixed to a post 59, which depends centrally from frame 18 and serves to support one end of the latte-r from and in spaced relation with a base plate 60. The other end of frame 18 is supported from base plate by an end frame 61, which is secured by screws 62 (Fig. 2) to said end. The armature hinge arms 56 and 56 extend along the inne-r faces of their armatures in parallel relation (Fig. 7) and beyond the armatures are offset outwardly and terminate with cylindrical ends 63 and 63', the axes of which are paralleh Such ends are disposed closely adjacent the end frame 61.

Both the armature hinge arms 56 and 56 are operated from a common drive shaft 65, which is disposed between and slightly above these arms. Theshaft 65 is rotatably mounted and adapted to be driven from an internal combustion engine and in .proper timed relation therewith. In this particular case, it is adapted to be driven at crankshaft speed from a four' cylinder, four cycle engine. The shaft 65 has a bearing near one end in the end frame 61 (Fig. 6) an intermediate bearing in a lug 66 depending from frame 18 and a bearing near its other end in the post 59. lThe shaft extends beyond the latter and'carries a cam 67 to actuate the distributer arm 34, hereinbefore referred-to. The shaft 65 has formed integrally therewith two cams 68 and 68 for operating the hinge arms 56 and 56 respectively. These cams are alike but diametrically opposed on shaft 65 They are also spaced one from the other longitudinally on this shaft although both are arranged 1n close proximity to end frame 61 Each has a dwell portion of somewhat less thanA 180 degrees angular extent. The remaining portion of the periphery of each cam is made up of a rise portion and a drop portion,these two portions gradually merging together as shown. The active portions of cams 68 and 68 are opposed so that While one is functioning to lnove its armature away from its poles, the other cam permits 'the other armature to move back toward and into contact with its poles. The

armatures 20 and 20 thus'work substantially in alternation although not in exact alternation. 1

The armatures may be moved intheirv flights ."away from their poles -in either of two ways. .They vmay be'moved .entirely by \an inelastic (see Fig. 4)

-68 or they may manner and thereafter be moved the remaining distance by the expansive action of prepviously stressed elastic 68. The follower with an .adj ustable 69 is lifted, one end being on follower 70, thereby 'urging by adjustments results.

'trated position, or beyond various otheran v spending to turn freely `on and is upturned .transmission of force from theircams 68 and be initially movedfa very short distance awav from-their poles in-this A meansf The inelastic transmission 4is effected by the following mechanism. A lever, 69 (Figs. 4 and 7) is mounted intermediate 'its ends the cylindrical end 63 of the armature hinge 'arm 56. A' cam` follower, comprising an arcuate flange 70 bent outwardly at right angles from the free end of an S-sha-ped arm '7 1 of metal plate, is interposed between one end of lever 69 and its cam ed on a'stud 73 (Figs. 4 and 7) secured -to a lug 74 on frame 61.

post 75 which depends from frame 18 (Fig.

The lever 69, at its other end is provided abutment in a screw 76 (Fig. 4), designed' to bear against the lower end of a pin 72,. (Fig. 6) in- 26 and. base -plate thus tends to raise the hinge arm''and the lever 69 carried thereby,

whereby the llever -caused'to bear on in 77 and the other end being caused to bear the latter toward its cam 68. The pin 77 vmay be held'against upward movement beyond `the illustrated position or, to-be described, it may be held against .upward movement beyond certain other and higher vertical positions. When this pin 77 is held from moving upwardly beyond the.illustratedposition, a direct or inelastic drive of the armature 20 from cam 6 Thus, the pin 77 .forms a' fulcrum for'le'ver 69 and, as the free end of the latter is depressed by cam 68, the hinge arm56 is lowered and armature 2() is priedof its poles, to -which it was theretofo're held by the-strong' force of magnetic attraction, and moved away from its po es the required distance:

er to hold the lfulcrumpin 77 against 'upward movement beyond the illushigher vertical positions, a cam 79 is arranged to bear on the upperend of pin 77, asshown in Figs. 1 and 4. This cam' and the correc'am79' are fixed to a. shaft 80 near opposite ends thereof. This shaft,.which ex- -tends transversely 'across frame 18, .is seated in. semi-circylar bearin' s\forine u r 'ends of the describe posts 43 an' cated forwardly 'of cross bar 41:2' It is held in each of these bearings` by a strap 81, of which underlies the cross bar 41 "a fiilcrum'.. The stra'p"'81 passe s. acrossthe :downwardly 'by dental turning of the same shaft 80 has fixed. thereto a-lever 83, whereby the angle a shown ting a be raisedi to various higher-positions.

arm 71 is pivotally Amount of the 'armatures by In thecase of the fol' of force described, iseiiected by the expansive o, lower 71', the pivot stud 7 3 is secured to a the 'shape of- 7 7 whichis mounted to slide freely in a lug 78 formedon frame 18.- An armature return spring terposed between armature i60 tends to hold the armature to-its poles and has a projection 88,entering the lower end the spring.

' mature and d ing of the drive spring ing to the position of to bear againstthe saine. as-

top of shaft 80 and its other end is drawn'` a screw shaft whereby easy or acciis resisted. The

a friction on a it ma be. turned to simultaneously 'move cams' 9 to various positions of adjustment. It will Abe noted that the cams 79 `may be turned throughout a certain range (through in Fig. 10) without permitchange in' fulcrum Apins 77 and 77 this range,the'cams will permit these pins to the cams are positioned, as last mentioned, the movement of the armatures away. their poles', after the preliminary prying o the inelastic stressed elastic means. To secure this action, a drive spring 84 is interposed between a rearwardly offset lug 85 on le'ver 69 and an abutment 86, adjustably secured to cross ba'r 41 (Figs. 1 and 5). The abutment 86 has a long depending guide 87 action of previously vundue transverse fiexu-re and the abutment 8i;

o It will be seen that, if pin -77I is free to rise above the illustrated position, the first action following the depression of cam follov'ver 70 by cam about the cylindrical end .63 of the armature hinge arm as a fulcrum. cause the armature is held firmly toits poles 'by-magnetic attraction and because the pin 77 is free to rise. Thus, the outer end of lever 69 is raised and the drive spring 84' is 4thereby 82 so -as to create transmission the vertical position of the If moved beyond When from Y extending into the springto 'restrain it from 68 will be to tilt le'ver 69 This follows be placed under stress. This drive spring, even when. stressed as much as possible with the il-l lustrated arrangement, is insufficient Atoever- 8 come the force of magnetic attraction whic holds the armature to its poles. Consequently, the stressin of the drive spring continues until the pin 77V ,is arrested in its upward movement by cam 79. Then pin 77 functions as a fulcrum for 1ever69 pried of its"poles by the described inelastic transmission of force from cam 68. Immediately following the prying 20 from its poles, the'magneticattraction on d the armature is so diminished by the creation between the arthat the previously a .very small air its poles,

stressed drive sprii'ig 84' is enabled to move the armature-andmore rapidly than it would of ev'en gap be moved by cam 68,1 Consequently, spring 84 expands and, the inner end of lever 69 temporarily. serving as fulcrum, moves the lever and thus the armature 20.

It will be obvious that the degree of stressmay the in i's allowed to rise higher. will also :be' o vf10us .that the time when the-'armature off of armature and the armature is leaves its poles with relation to the angular position of shaft 65 may be varied by the setting of pin 77. When the latter is positioned as lllustrated, the armature leaves its poles at an earlier position in the revolution of vshaft 65, or in what maybe termed full advance position. If, however, the cams 79 be` so set as to allow the pins 79.to rise above the illustrated position, the armature leaves its poles at a later time in the revolution of shaft 65, or in what may be termed retard p`osition. The production of a spark from' the magneto depends on the time of separation of the breaker points and 26 and such separation is effected by the movement of armaso that it is possible, should'such a condition be' desired to arrange for advanced spark when spring drive of the armature is used.

The mechanism for separating the breaker points 25 and 26 will now be described with' particular reference to Figs. 5, 6 and 7. The plates 57 and 57, heretofore described as' fixed to the armatures 20 and 20', extend beyondtheir armatures (to the left as viewed in Figs. 5 and 7) and the free end of each l is given a quarter turn, thereby `forming a horizontally disposed lug 90. Passing freely through the lugs 90 and' 90', as best shown in Fig. 5, are screws 91 and 91 which are disposed on opposite sides ofthe hollow rectangular support 52, heretofore referred to as carrying the breaker point 25. These' screws also pass freelythrough a lever 92, one naar each end thereof, andare supported from the lever by their heads which rest on' crimped portions of the lever. This lever 92 encompasses the described stem 5 1l and centrally between its ends is-fulcrumed on the upper face of the support 52 or strictly on the upper face of the Hange of plug 51 which Hange rests on support 52. The -lever 92 is crimped at its middle to afford substantially the equivalent of a knife edge bearingto form a suitable fulcrum and' the crimped i vends of the lever afford similar` fulcrum bearings for engagement by the heads of screws 91 and 91.^ Thesezscrews, below their respec-l tive lugs 9() and 90v carry adjustable abutments in the shape of nuts, 93' and 93', and lock nuts 94 and 9 4 'to hold the abutments` in their adjusted positions.

The arrangement described permits the one l interrupter to be operated alternately by the on the head of screw 91.

20 also serves to separate the breaker points at an intermediate point in its downwardlpoles to reach the illustrated position the '90 eventually came4 into engagement with abutment 93 and tilted one end of lever 92 downwardly about its central crimped porj tion as a fulcrum, thus raising the other end of lever 92 until abutment 93 engaged lug 90. After armature v20 had moved far -euo-ughf away from vits poles to take up all the slack v in t-he connections described, further downward movement of armature 20 served 'to depress the support 52 and thus separate breaker point 25 from breaker point 26. The raised end of lever 92 then served as a fulcrum, bearing on the head of screw 91. The' arrangement is such that the points 25 and 26 are separated at an intermediate point in the Hight of armature 20 away from its poles. As armature 20 moves back toward its poles, the spring 53 causes the points 25 and 26 to be again engaged and justas lthe armature 20 is about to seat on its poles 12', the armature 20 starts to leave its poles 12. The armature20, in its Hight away from its poles,causes lug 90 to engage abutment 93v and tilt the right handend of lever 92 (Fig. 5) downwardly, raising the other end untilall slack in the connections is taken up and thereby depressing support 52, with the raised end of lever 92 bearing as a fulcrum Thus, the armature movement.- B suitable adjustment of the parts, the brea er points are caused to separate at the optimum point in the downward' Hight of each armature. f v

lt will be apparent that the breaker point I operating mechanism described is characterized by an equalizing function. That is, the separate vconnections from each armature to the breaker point 25 do not have to be carefully adjusted to a nicety to secure exact balance. This follows because the lever 92 in itself formsan equalizer. both screws 91 and 91 function'in each downward movement of the breaker point, a change inthe effective length of one may be madek without making a corresponding chang? in .the effective length ofthe other and the breaker points will nevertheless open at the same point inthe downward Hight of each armature. *A change in the adju tment of one abutment nut, as 93, will var the effective lengt-h of its screw 91 and a ect a change in the timevof operation of breaker point 25 by armature 20 but the change will necessarlly efectan equal change in the time of operation of thebreaker point by armature 20.

It has been shown heretofore wherein/a Inasmuch as les change in the timing of the sparks from the times when spring drive is Aused for the armalso.

turethan when thelatter `is directly driven.

It 4is often desirable to .vary the timing when direct drive is used for the armature and for such purpose means are provided' for varyinv'the.vertical`position of the upperbreaker point 26. Such means are preferably controlled from shaft Strand, as shown in Figs.

4. and6, a'cam 95 is formed integrally with anden the central portion of shaft 80. Cam 495 is adapted to engage a rocker arm 96 pivotall mounted on a pin 97 Pin 97 is secure at its ends in' laterally spaced dependmal up ing ears formed on a washer like piece 98 which is held in place between the lower face of cross bar 41 and the flange of the described bushing45: The inner end of rocker arm 96 straddles the interrupter casing'46 and bears against .the iiange 48. Consequently, when armr 83 is so turned as `to cause cam 95 to lift the outer 'end of rocker arm 96,y

the inner end thereof forces iange48 downwarclly `and causes breaker point 26 to be lowered. The lowering of point 26 naturally c ausesa later disengagement of point 25 therefrom. As pointed out before, spring 41' tends to hold breaker point 25 in its norr position and therefore acts lto restore this breaker oint when cam 95.is moved back .into the position illustrated.

Referring to Fig. 10, it will be seen that shaft' 80 v can be turned vthroughout a certain range -invwhich the breaker point easing 46, and thus the upper breaker oint 26, can be moved without causing a c iange in f the position of the ulcrum pins 77. Such range is designated by the angle a. When the cam 79 is turned so that line y coincides l have been moved into its uppermost posirect drive.

tion. At such time, the left liand rounded end of lever 96 will be resting on the right hand 'side of cam 95, i. e., the side which is A 'tangential to shaft 80. The opposite side of cam 95 is not exactly symmetrical with the sid-e just referred tor-the cam being widened out along this side, as indicated at 99.`

engage ulcrum pins l77.at somepoint in the angle 1). Itwilli'be seen that/ under such conditons'the upper breaker 'oint 26 will be positioned atJa level slight y lower u than the uppermost position, which it occupies when the cams 79 are positioned for .di- During impulse drive, the tim- Thisside 99 is engaged by lever 96 dur-4 ing impulse drive, i. e., when.v cams 79 ing o f the spark is controlled by controlling the time when the armature ispried oi its poles and the breaker point 26 is not re 4quired'to,move^'du rin, 'gj such drive. It is necessary, however, that this breaker point 26 be properly positioncdso that the movable breaker point 25 will separate from it at thev optimum point in the downward flight 'of the 'armature and the'part'99 vfunctions to so position point 26. For impulse drive where the armature is driven by a spring always at substantially constant speed, there is one point in .the downward flight of -`the armature where the best results are obtained and this point has been termed the optimum point. For direct drive, there is another factor which has to be taken into consideration, viz,

the armature speed, and this .factor is variable so 'that there will be no definitely fixed optimum point for all speeds. "lhere will, however, be van foptimum range of armature movement during which -the breaker .points should be opened tosecure the most favorable' results. That range will include the aforesaid optimum point as .well/as points on either side thereof. Thus, it is necessary that the cam 95 be arran' ed vto move the upper breaker point 26 botg-h above and below the iXe'd ositionwhich it occupies during impulse rive. Also, it is necessary to s o move the breaker point 26 to secure'timing of the spark by this A particular method.

That is, since the armature, when operated by direct drive, always leaves its polesat predetermined points in the revolution .of

drive shaft 65, the timing has to be eiected i in this instance by varying the point in the armature iight at which the breaker points are separated. Necessa-rily, -when provisions are made for a. range of spark advance, this means that the upper breaker point must be capable of being positioned above as Well as' at and below the point which it occupies on impulse drive, wherefore the non-symmetrical cam 95 is employed. ABy this arrangement, full retarded or full advanced spark can` be obtained.

" The upward pressure of spring 53 on suport 52 1s out of line with the vertical center ine of tlie breaker point plunger 50,'as will be .apparent from an inspection of Fig. 6. To avoid this possible disadvantage, the arrangement shown in Fig. 9 maya be4 used. As .there shown, a support 100, corres-pond ing functionally `to support 52 butslightly diierent in shape, rests on thev upwardly crimped bearing 101 formed on the free end of a lever 102 and between two spaced` lu 103 struck upwardly therefrom. The lever is pivoted at 104 to the bearing 66and is urged Y upwardly by a sprino 105 correspondin to spring 53 but locatednsomewhat to the rigght of the position formerly occupied .by spring 53.- The arrangement shown in-Fig. 10 permits. the upward 'spring pressure to be apiai armature moves through one cycle, that is',

Vawayfrom. its poles and subsequently hack into contact therewith, Iduring a half revolution of-shaft 65 and these cycles occur in alternation so that ,two sparks are produced during each revolution of shaft 65 at symmetricalintervals. Thus, the magneto, .when shaft 65 is driven at crank-shaft speed, will produce the ignition sparks necessary for a four cylinder, four cycle engine,-the ignition E. M. F. from the magneto being distributed at proper intervals successively to the several cylinders by the distributer D, as above described. As one armature, say 20, moves away from its poles, thereluctance of its magnetic circuit is greatly increased and lwhen the breaker points and 26 separate, the chok ing winding 21, which has theretofore tended to restraina change of flux, is opened 'anda sudden lchange of fiux results thereby generating an E. M. F. in coils 22. As the 'other armature 20 moved toward and into Acont-act with its poles justiprior tothe downward movement of armature 20, the reluctance of the magnetic circuit of which it is a part was,

also changed althougha flux change was, to a large extent, restrained because the choke windings 21-were short circuited during` the latter part of the returnv travel of armature 20. The separation of breaker' points 2'5 and 26 serves, as will be seen'from Fig. 8, to open both the choking windings 21 and 2l so that two flux changes, one due to the downward movement of armature 2O and the other due to the upward movement of armature 20', are producedaand by the common 'control through the one set of breaker points these two flux changes are made to simultaneously produce two E. M. F.s vone in windings 22 and the other in windings 22. These generating windings are interconnected so that the two E. M. F.smre merged. As shown, they are added so that a better spark is produced by the two cooperating units than could be obtained with either when working separately.

The control of the two units of themagneto by a single set of breaker points constltutes one feature of this invention". y

Another important feature of the invention relates to the arrangement whereb one set of breaker points mayl be loperated rst by one and then by another armature of a dual arma. ture type magneto, whether or not that vmagneto is of the particular type disclosed in said copending application. 'As one armature moves away from its poles, it rocks the operating lever 92 by means of the connecting.

screw, such as 91and the other screw, such as-4 91, after it has been lifted until its abutment 93engagesth'e armature abutment 90, serves o anchor one end oflever 92 while the plunger lbalanced act-ion is eliminated. The/arrangethought to be important for by locating some vbreaker point, thereby causimer 'the lower` 130 50 is lowered by continued downward movement of the armature, separating the'hreaker points 25 and 26. A After the irst'named arma-l ture has returned to its poles and the other a1'- be noted that the lever 92 serves as an equalizer and'insures that the breaker points separate at the same time irrespective of which armature operates them. After either armature has moved adenite distance away from its poles the points separate andthe movev ment necessary for' one armature to effect a separation of the points is the same-as that necessary for the other armature. Thus, as pointed out above, the necessity for fine and careful adjustments of the abutments 93 and 93 on their respective screws to secure nicely ment is suchthatit inherently result-s in a nice balance .without any attention whatsoever. rlhe particular disposition of parts of the interrupter operating vrneclurnism` is also 95 parts above, others'below, and others on opposite sides of the dri've shaft 65, it is possible to apply the mechanism within the close limits of the small space available between'the drive shaft and the two armatures and nevertheless have it function effectively and without interference with other closely ad jacent parts. The remaining features of the invention are independent of whether the magneto is of the dual armature type.` Chief among these features is the provisionfor varying the 1ocation of the upper breaker point l26, wherebyt-he time of the se aration of the breaker points may be varie to retard or advance the spark. This feature is important in any case, regardless fof the type of armature operating mechanismj employed. The upper breaker point,.not being;.,subjected to any great stress, can thereforefbe movably 1pported for adjustment'by parts of relatively 115 ,ight construction which presentle'ss resistance to movement and enable the adjustment to be effected while the magneto isdn. operation andwith very little effort. Thisfeature also 1s important in a magnetoof the type lao wherein both spring drive and direct inelastic drive areused for moving 4the armatures. away from their poles. It enables a division Y of the work of spark control betweenzth'e two formso-f drive and enables just as rmuch con- ,12rtrol of the spark so far as retardation is concerned, whether direct or spring drive is used. When direct. drive is used, the-retardation of spark is effected by lowering the lupper' breaker point to be ,disengaged from its mate at a later time inthe flight of. the armature away from its poles. When s ring drive is used, the late spark is eiecte by delaying the time of initiation of the downward Hight of the armature. The two means for spark control thus may be llogically divided between f the two forms of drive, providing all the 'spark control desired` with either form of drive. A retarded spark with a spring drive of the armature is available for starting purposes and with direct drive there is available drive) or various between the two extreme. limits.

a full advanced spark or a fully retarded spark (as late as that available with spring' degrees of spark retard The invention has been disclose-d herein,

in an embodiment at 'present preferred, for' cuits including two sets nof magnetic poles,

' com rising cooperating4 reaker' able means tending to hol them en reciprocable means forming part of said cir,- cuits for connecting iist0 one and tiren theJ other ofsaid sets of poles','a normally short circuited choke winding for each magnetic circuit, a generating winding'for each circuit, a single set of relatively movable breaker points for Asimultaneously opening and'subsequently simultaneously closing said choke windings, and means operable first from one armature' and then ,from the other for sep'- aratiiig said breaker pointsl at an intermediate. point in the Hight of each armature away from its poles, and connections between said generating windings forl merging the currents produced therein;

2. A me neto, comprising, two magnetic circuits eac having a set of poles, a generating'winding and a choke winding associated with each circuit, a reciprocable armature for each circuit to periodically connect and disconnect its set ofpoles, -means for moving first one and then. the other armature away from its poles, a'single set of cooperating an relatively movable breaker points'with yieldable means tending to hold them engaged, and means whereby 'each armature at an -intermediat'e point in its flight away from `its oles separates said breaker points, the latter eing connected in a closed circuit with both said choke windings and when separated adapted to' simultaneously open the same, and connections between said generating windings for merging the currents produced therein.' A 3. In a magneto,t having two armatures with means for moving first one and then the other away from its oles, an interrupter oints with yiel aged, and means foreach armature for moiving one of said points away .from the.- other d iiights of the Leeavie' vby `and duringthe Hight-of each-armature' away from its poles, and an equalizer con-A nection between -bothsaid means and the last named breaker point.

4. In a magneto, having f twoarmatures with means formoving first one and then the other away from its poles, 'an interrupter comprising cooperating breaker points and yieldable means for holding them in engagement,'a lever, a eonnectionhbetweenone .end

lever being'pivotally connected intermediate its ends to saidpart.

5. In a magneto vhaving two reciprocable armatures operablek substantially in alternation, an interrupter adapted tojbe .operated alternately by said armatures, and comprising cooperating breaker -points with yield- -of the lever and one of said armatures and a connection between the opposite end of the -lever and the otherarmature, and apart movable with one .of said breaker points, saidable means tending to hold them engaged,

a slidable support `to which one o breaker points is iixed, a leverv carried by and pivotally connected intermediate its ends to said support, connecting devices one for eacharmature depending from said lever `and disposed on opposite sides of said 4support, an abutment on each which its connecting device .freely passes,

and an abutment on each device adaptedlto be' engaged by the corresponding armature armature throughV said abutment for separating said breaker points at a predetermined point in the movement of each armature. i' l, 6. In a magneto, having two sets of magnetic poles, an'- armature for each set movable into and out ofcontact therewith and means for moving first one and then the other armature so that during part at least 'of the flight of one armature away from lits poles the other armature is'in contact with its poles,

a single 'interrupter having cooperating breaker points one of which is adapted to be from the other 'first by one ar' moved awa mature an then by the other during the poles,

named breaker point, alever ulcrumed intermediate its ends thereto, and connections the-flight of its armature away from its poles.

to Iegarate said breaker points.

armatures awa 'from their a member movable with said last.

n a magneto, having two sets of magnetic oles and an armature for each set movable into and out of contact therewith, a drive shaftdisposed between said armatures, an interrupter casing car ngi `a' breaker point su ported above said s ing brea er oint slidably supported in' said aft, a cooperatcasing, :a lio 'ow'support connected to movef 15,0, .A

with said last named breaker point and loose- 1y encompassing said drive shaft with freedom for vertical movement, a spring underlying said support for yieldingly holding said breaker vpoints engaged, a. lever Centrally and pivotally supported from the upper end of said support, a connection between one end of said lever and one armature, andra connection between the other end of said lever and the other armature.

8. In a magneto, having'two sets of magnetic poles and an armature for each set movable into and out of contact therewith, a drive shaft disposed between said armatures, an interrupter casing carrying a breaker point supported above said shaft, a cooperating breaker point slidably supported in said casing, a hollow support connected to move with said last named breaker point and looselyl encompassing said drive shaft with freedom for vertical movement, a spring underlying said support for yieldingly holding said breaker points engaged, a lever centrally and pivotally supported from the upper end of said support, headed members, one foreach armature and disposed one at each end of said lever, said members passing freely through the lever and supported therefrom by their heads, abutments one for each armature and movable therewith through which abutments said members freely pass, and abutments one for each member and adjustably mounted thereon and each underlying its armature abutment. I

9. In amagneto of the type wherein an armature is moved into and out of cont-act with magnetic poles, and wherein a choking winding is arranged in an electrical circuit which can be opened and closed by a pair of relatively movable breaker points, mecha.- nism adapted for operation from an engine for moving the armature away from its poles, said mechanism including two relatively movable parts and a spring interposed therebetween and adapted to be stressed by their relative movement, means for preventing relative movement of said parts and the stressing of said spring when desired and causing the armature to be moved away from its poles solely by an inelastic transmission of force from' the engine, means for moving one of said breaker points away from .the other operable by movement of the armature and at an intermediate point in its flight away from its poles, and means for moving the other breaker point to vary the point in the flight of said armature at which said breaker points will separate.

10. In a magneto of theftype wherein an armature is moved into .and out of contact with magnetic poles, and wherein a choking winding is arranged in an electrical circuit which can be opened-and closed by a pair of relatively movable breaker points, mecha.- nism adapted for .operation from an engine for moving the armature away from its poles,

said mechanism including two relatively r, movable parts and a spring interposed there-` between and adapted to' be stressed by their relative movement, means for preventing .relative movement of said parts and the stressing ot said sprinfr when desired and causing the armature tothe moved away from.' its poles solely by an inelastic transmission ll. In a magneto of the type whereinfan armature is moved into and out of contact with magnetic poles, and wherein a choking winding is arranged in an electrical circuit which can be opened and closed by a-pair of relatively movable breaker points, mechanism adapted for operation from an engine for moving the armature away from its poles, said mechanism including two relatively movable parts and a spring interposed therebetween and adapted to be stressed by their rela-tive movement, means for preventing relative movement of said parts and the stressing of said spring when desired and causing the armature to be moved away from its poles solely by an inelastic transmission ot force from the engine and at. an earlier time then when operated by said spring, .means for moving one of said breaker points away from the other operable by movement of the armature and at an intermediate point in its flight away from its poles, and means operable when relative movement of said parts is prevented to vary the time of separation of said breaker points.

12. In a magneto of the type wherein an armature is moved into and out of contact with magnetic poles, and wherein a choking winding is arranged in an electrical circuit which can be opened and closed by a pair of relatively movable breaker points, mechanism adapted for operation from an engine for moving the .armature away from its poles, said mechanism including two relatively movable parts and a spring interposed therebetween and 'adapted to be stressed by their relative movement, means for preventing relative movement of said parts and the stressing of said spring when desired and causing the armature to belmoved away from its poles solely by an inelastic transmission Aof force from the engine,.means for moving one of said breaker points away from the other operable by movement of the armature and at an intermediate point in its flight away from its poles, and means controlled by said preventing means and operable when the armature is moved into and out-'of contact with magnetic poles, and wherein a choking winding is arranged in an electrical circuit which can be opened and closed by a pair of relatively movable breaker points, mechanism adapted for operation from an engine for moving the armature away from its poles, said mechanism including two relatively movable parts and a spring interposed 'therebetween and adapted to be stressed by their relative movement, lmeans for preventing relative movement of' said parts and the stressing of sai'd spring when desired and causing the armature to be moved away from its oles solelyv by an inelastic transmission of orce from the engine, means for moving one of said breaker points away trom the other operable by movement of the armature and at an intermediate point in its flight away from its poles, and means operable when relatlve movement of said parts is prevented to Y vary theposition of the other'breaker point to varythe time of separation of said breaker points.

14. In a magnetoof the type wherein an armature is moved into and out of contactl with magnetic poles, and wherein a choking winding is arranged in an electrical circuit which can be opened and closed by a pair of relatively movable .breaker points, mechanisin adapted for 'operation from an engine for-moving the armature away from its poles, said mechanism includingtwo relatively movable parts and a spring interposed therebetween andadapted' to be stressed by their relative movement, means for preventing relative movement of said parts and the stressing of said spring when desired and causing the armature to be moved away from its poles solely bfy an inelastic transmission of force from the engine, means for moving one of said breaker points away from the other operable by movement of the armature and at an intermediate point in its flight away from its poles, and means controlled, by said preventing means and operable when the armature is moved by said inelastic transmission to vary the position of the other breaker pointto vary the time of separation of said breaker points. A

15, In a magneto, wherein an armature is moved toward and away from magnetic poles,

and wherein ,a normally short circuited chok- .ing winding -is arranged to be periodically opened and subsequently closed by a pair of I ,relatively movable breaker points, means operable during the movement of said armature away from its poles to Jmove one ofl said breaker points away Vfrom the other tojseparate the same and open said windings, and

means formoving the other breaker point an inelastic transmission o out of contact with magnetic by an elastic transmission of force, means n controlled by movement of the armature awa from its poles for moving one of said' brea er points away from the other and for separating said points later when the armature is moved by an elastic transmission of force than when moved by the inelesatic transmission of force, and means for moving the other breaker point to secure a range of timing of the spark when the armature is moved by an inelastic transmission of force.

17 In a magneto, of the type wherein an armature is moved vinto and out of contact with magnetic poles and wherein the armature may be moved away from its poles sc le-l ly bv an .inelastic transmission from the drivev shaft or partly by said transmission followed by the expansive action of previously stressed elastic means, a movable member effective during part of its movement to change from lone form of transmission to the" other, and

means operable by said member during another part of its movement to vary the timing of the spark from the magneto.

18. vIn a magneti), of the typewherein an armature is moved'into and out of contact with `magnetic poles and wherein the time of product-ion of the spark depends on the time of separation of a pair of relatively movable breaker points, driving means for movin the armature away from its poles solely Iy an inelastic transmission. of force or part y by said transmission and partly by' an elastic transmission of force, means Afor separating said breaker points at an intermediate point in the Hight of the armanL from its poles, a movable member.

ture away effective over part of its range of movement' to vary the time of separation of said breaker points .and over another part of saidfirange to change the armature driving means from one form of transm1ss1on to the other.

'19.l In a magneto, of the type wherein an armature is movedvinto andout of Contact with( magneticpoles and wherein the time of production of the spark depends on the time of separation of a air of relatively movable -breaker points, riving means for moving solely or partly by said transmission and partly by an elastic transmission of force, means for the armature away from itspoles by an Ainelastic transmissiomof force moving one of said breaker points away from the other at an intermediate point inthe flight' of. the armature away from itsfpolves, a movable member effective over part `Aof its rangeof movement-to move thel other breaker v point to vary thetnneof separation of said f pointsand over another part of said rangi':

iov

tochange the armature driving means from one form of transmission to the other.

20. In amagnetoyof the type wherein an armature is moved into and out of Contactwith magnetic poles and wherein the time ot' production of the spark'depends on lihe time of separation of a pair ot' relatively movable breaker points, driving means for moving the armature away from its poles solely by an inelastic transmission of force or partly .by said transmission and partly by an elastic transmission of force, means for moving one of said breaker points away from. the other at an intermediate point in the flight of the armature away from its poles, a movable member effective over part of its range of movement to move the other breaker point to vary the time of separation ot' said points and when moved beyond said range. to .cause the armature to be moved away from its poles by said elastic transn'iission of force.

2l. In a magneto, of the type wherein an armature 1s moved into and out of Contact with magnetic poles and wherein the timev4 of production of t-he spark depends on the time of separation of a pair of relatively movable breaker points, driving means for movingr the armature away from its poles solely by an inelastic transmission of force or partly by said transmission and partly by an elastic transmission of force, means for moving one of said breaker points away from the other at an intermediate point in the flight of the armature away from its poles, a control member effective when moved a certain distance from one position to change the armature driving means from said inelastic to said elastic transmission and when moved less than said distance from said position to vary the posit-ion of the other breaker point. to vary the time of separation of the breaker points and secure'a range of spark control from full advance to full retard while the armature is being driven by said inelastic transmission.

22. In a magneto, of the type wherein an armature is moved into and out of contact with magnetic poles and wherein the time of production of the. spark is dependent on the time of separation of a pair of relatively movable breaker points, mea-ns for movingr the armature, means operable during an intermediate part of the -flight of the armature away from its ypoles to separate said breaker points, and mea-ns operable while said armatureis in motion for adjusting the4 position of one of said breaker points to varv the time of separation of the same.

23. In combination, a fixed guide, a mem` ber slidable therein and carryingr a breaker point, a second member slidable in the first member and carrying a emperating breaker point, means for periodicallv movingr one of said members to carry one of said breaker points into and out of engagement with the other, and means for moving the other niembcr tovary the time at which the breaker points will separate under the action of the first named means.

24. In combination, a slidably supported member carrying a breaker p'oint, a. second slidably supported member carrying a cooperating breaker point, means for periodically moving one of said members to separate and subsequentlv reengage said breaker points, and means for moving the.v other member to adjust the position ot its breaker point and thereby vary the time at which the breaker points will separate under the action of the first named. means.

In combination, a fixed guide, a member. movably mounted therein and carrying a breaker point` yieldable means tending to hold said member in a predetermined/position, a. second movably mountedl member carrying a coopera-ting breaker point, means for periodically moving the second member to carry its breaker point out of and subsequently into engagementl with the other breaker point, and means for moving the other member against the action of said yieldable means to vary the position of the other breaker point and thus the time atA which the breaker points will separate under thcaction of the first named moving means.

26; In a magneto, of the type wherein an armature which' is movable into and out of contact with magnet-ic poles may be driven in its'fiight away from said poles either en- 105 tirely by an inelastic transmission oi force or initially bysuch transmission followed by the expansive action of previously stressed elastic mea-ns and wherein the time of production of the spark is dependent on the time of separation of a pair of relatively movable and cooperating breaker points, means operable to separate said breaker points during the flight of the armature away from its: poles, shiftable means for changing from one. form of armature. drive to another, and means -controlled bv Said shiftable'mcans to cause said breaker points to separate at a different point in said flight of the armature when the latter is operated by one form of drive than with t-he other.

27. In a magneto, of the type wherein an armature which is movable into and out of contact with magnet-ie poles may be driven in its flight away from said poles either entirely byan inelastic transmission of force or initially by Asuch transmission followed by the expansive act-ion of previously stressed. elastic means and wherein the time of produrtion of the spark is dependent on the time of separation of a pair of relatively movable breaker point and vthereby vary -the time in and cooperatinv breaker points,' means op-I' said Hight at'whch the breaker points sepa- 1 erable at a preieternnedpoint durn the rate. flight of the amature away from its po 'es to In testimony whereof we have axed our A moveone of the breaker points, and-:means signatures.

operable )vhen' the driving means foishe ,Il armature is changed from the sewnd-'name1\ PHELPS BROWN..- to the first-named f orxn to move the other IRA E. HENDRICKSON. 

